I was recently TASing something when 3-4 savestates started to become corupted on GENS 9.5b. The main problem seems that the savestates are specifically linked to the .gmv file and I can't play the .gmv because it has all it's data wiped except for the author name. I only know know this because I viewed in on a hex editor. I tried starting a new file but because of the linked savestate stuff, all the save slots are empty. I know some of the savestates are still intact but I can't reload the movie from them because I can't play the .gmv. I've also had a look at undoing my laptop, but I didn't have system restore enabled.
Does anyone know any way to get round it?
If you had autobackup enabled, there should be a [moviename].bak.gmv file which might still have good data.
It sounds like what happened is you played past the end of the movie and then forgot you weren't recording. You should really be using Gens 10, it has safeguards against that kind of thing.
How fleeting are all human passions compared with the massive continuity of ducks.
I think savestates in Gens aren't exactly linked to the movie file, they only have to match up with the movie's filename (like "GAMENAME - MOVIENAME.gs1") so you could easily "re-link" them to a movie that works and then load the savestate in non-read-only mode, if any of the savestates still have valid movie data in them that is. You could also try the "Load State" menu option that lets you load any savestate file from a file open dialog.
Nitsuja's solution did solve the problem but the problem came back again. This time it's a lot worse since I was 80% of the way through as opposed to 30% the last time. It seems on odd ocassions if I load a savestate it will load from the power on and the .gmv gets treated like a load from savestate file. The main problem this causes is that the other healthy savestates to have corrupted input i.e all directions and buttons are being held.